WAR is influenced by position so if 2 players have identical stat lines, but one is a middle infielder while the other is a first baseman, the middle infielder's WAR will be higher than the 1B since you expect to generate a lot more offense from your corner IF/OF than your infielders. Zobrist has played over 60% of his career games either at 2B or SS, so his offensive contributions are generally much greater than the league average middle infielder than Konerko, who, for most of his career, was just kind of an average offensive 1B.